<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
        var cities=[{spell:"tianmen",city:"天门"},{spell:"tianjin",city:"天津"},{spell:"tianshan",city:"天山"},
    {spell:"suizhou",city:"随州"}]    
    /* 天或tian  开头的  将city添加到一个数组中 */
    /* var allCities=[] */
    var allCities=[];
    cities.forEach(item=>{
        if(item.spell.startsWith("t") || item.city.startsWith("天")){
            allCities.push(item.city)
        }
    })
    console.log(allCities)
    </script>
</body>
</html>